Internet Engineering Task Force E. Haleplidis
Internet-Draft University of Patras
Intended status: Informational K. Ogawa
Expires: September 5, 2009 NTT Corporation
X. Wang
Huawei Technologies Co., Ltd.
March 4, 2009
ForCES Interoperability Draft
draft-ietf-forces-interoperability-00
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on September 5, 2009.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
Haleplidis, et al. Expires September 5, 2009 [Page 1]
Internet-Draft ForCES Interoperability Draft March 2009
Abstract
This document describes the details of the interoperability test of
the Forward and Control Element Separation (ForCES) protocol that
will take place in the University of Patras in Rio, Greece, in the
fourth week of July 2009. This informational draft provides
necessary information, for all parties who wish to participate in the
interoperability test.
Table of Contents
1. Terminology and Conventions . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. ForCES Protocol . . . . . . . . . . . . . . . . . . . . . 4
2.2. ForCES Model . . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Transport mapping layer . . . . . . . . . . . . . . . . . 4
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Testbed architecture . . . . . . . . . . . . . . . . . . . . . 8
4.1. Local configuration . . . . . . . . . . . . . . . . . . . 8
4.2. Distributed configuration . . . . . . . . . . . . . . . . 8
5. Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. Scenario 1 - Pre-association Setup . . . . . . . . . . . . 9
5.2. Scenario 2 - TML connection . . . . . . . . . . . . . . . 9
5.3. Scenario 3 - TML priority channel connection . . . . . . . 9
5.4. Scenario 4 - Association Setup - Association Complete . . 10
5.5. Scenario 5 - CE query . . . . . . . . . . . . . . . . . . 10
5.6. Scenario 6 - Heartbeat monitoring . . . . . . . . . . . . 10
5.7. Scenario 7 - Simple Config Command . . . . . . . . . . . . 11
5.8. Scenario 8 - Association Teardown . . . . . . . . . . . . 11
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
Haleplidis, et al. Expires September 5, 2009 [Page 2]
Internet-Draft ForCES Interoperability Draft March 2009
1. Terminology and Conventions
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Haleplidis, et al. Expires September 5, 2009 [Page 3]
Internet-Draft ForCES Interoperability Draft March 2009
2. Introduction
Forwarding and Control Element Separation (ForCES) defines an
architectural framework and associated protocols to standardize
information exchange between the control plane and the forwarding
plane in a ForCES Network Element (ForCES NE). [RFC3654] has defined
the ForCES requirements, and [RFC3746] has defined the ForCES
framework.
2.1. ForCES Protocol
The ForCES protocol works in a master-slave mode in which FEs are
slaves and CEs are masters. The protocol includes commands for
transport of Logical Function Block (LFB) configuration information,
association setup, status, and event notifications, etc. The reader
is encouraged to read FE-protocol [I-D.ietf-forces-protocol] for
further information.
2.2. ForCES Model
The FE-MODEL [I-D.ietf-forces-model] presents a formal way to define
FE Logical Function Blocks (LFBs) using XML. LFB configuration
components, capabilities, and associated events are defined when the
LFB is formally created. The LFBs within the FE are accordingly
controlled in a standardized way by the ForCES protocol.
2.3. Transport mapping layer
The TML transports the PL messages. The TML is where the issues of
how to achieve transport level reliability, congestion control,
multicast, ordering, etc. are handled. It is expected that more than
one TML will be standardized. The various possible TMLs could vary
their implementations based on the capabilities of underlying media
and transport. However, since each TML is standardized,
interoperability is guaranteed as long as both endpoints support the
same TML. All ForCES Protocol Layer implementations MUST be portable
across all TMLs. Although more than one TML may be standardized for
the ForCES Protocol, for the purposes of the interoperability test,
the mandated MUST IMPLEMENT SCTP TML [RFC3654] which will be used.
Haleplidis, et al. Expires September 5, 2009 [Page 4]
Internet-Draft ForCES Interoperability Draft March 2009
3. Definitions
This document follows the terminology defined by the ForCES
Requirements in [RFC3654] and by the ForCES framework in [RFC3746].
The definitions below are repeated below for clarity.
Control Element (CE) - A logical entity that implements the ForCES
protocol and uses it to instruct one or more FEs on how to process
packets. CEs handle functionality such as the execution of
control and signaling protocols.
CE Manager (CEM) - A logical entity responsible for generic CE
management tasks. It is particularly used during the pre-
association phase to determine with which FE(s) a CE should
communicate. This process is called FE discovery and may involve
the CE manager learning the capabilities of available FEs.
Forwarding Element (FE) - A logical entity that implements the
ForCES protocol. FEs use the underlying hardware to provide per-
packet processing and handling as directed/controlled by one or
more CEs via the ForCES protocol.
FE Manager (FEM) - A logical entity responsible for generic FE
management tasks. It is used during pre-association phase to
determine with which CE(s) an FE should communicate. This process
is called CE discovery and may involve the FE manager learning the
capabilities of available CEs. An FE manager may use anything
from a static configuration to a pre-association phase protocol
(see below) to determine which CE(s) to use. Being a logical
entity, an FE manager might be physically combined with any of the
other logical entities such as FEs.
ForCES Network Element (NE) - An entity composed of one or more
CEs and one or more FEs. To entities outside an NE, the NE
represents a single point of management. Similarly, an NE usually
hides its internal organization from external entities.
LFB (Logical Function Block) - The basic building block that is
operated on by the ForCES protocol. The LFB is a well defined,
logically separable functional block that resides in an FE and is
controlled by the CE via ForCES protocol. The LFB may reside at
the FE's datapath and process packets or may be purely an FE
control or configuration entity that is operated on by the CE.
Note that the LFB is a functionally accurate abstraction of the
FE's processing capabilities, but not a hardware-accurate
representation of the FE implementation.
Haleplidis, et al. Expires September 5, 2009 [Page 5]
Internet-Draft ForCES Interoperability Draft March 2009
FE Topology - A representation of how the multiple FEs within a
single NE are interconnected. Sometimes this is called inter-FE
topology, to be distinguished from intra-FE topology (i.e., LFB
topology).
LFB Class and LFB Instance - LFBs are categorized by LFB Classes.
An LFB Instance represents an LFB Class (or Type) existence.
There may be multiple instances of the same LFB Class (or Type) in
an FE. An LFB Class is represented by an LFB Class ID, and an LFB
Instance is represented by an LFB Instance ID. As a result, an
LFB Class ID associated with an LFB Instance ID uniquely specifies
an LFB existence.
LFB Metadata - Metadata is used to communicate per-packet state
from one LFB to another, but is not sent across the network. The
FE model defines how such metadata is identified, produced and
consumed by the LFBs. It defines the functionality but not how
metadata is encoded within an implementation.
LFB Attribute - Operational parameters of the LFBs that must be
visible to the CEs are conceptualized in the FE model as the LFB
attributes. The LFB attributes include, for example, flags,
single parameter arguments, complex arguments, and tables that the
CE can read and/or write via the ForCES protocol (see below).
LFB Topology - Representation of how the LFB instances are
logically interconnected and placed along the datapath within one
FE. Sometimes it is also called intra-FE topology, to be
distinguished from inter-FE topology.
Pre-association Phase - The period of time during which an FE
Manager and a CE Manager are determining which FE(s) and CE(s)
should be part of the same network element.
Post-association Phase - The period of time during which an FE
knows which CE is to control it and vice versa. This includes the
time during which the CE and FE are establishing communication
with one another.
ForCES Protocol - While there may be multiple protocols used
within the overall ForCES architecture, the term "ForCES protocol"
and "protocol" refer to the Fp reference points in the ForCES
Framework in [RFC3746]. This protocol does not apply to CE-to-CE
communication, FE-to-FE communication, or to communication between
FE and CE managers. Basically, the ForCES protocol works in a
master- slave mode in which FEs are slaves and CEs are masters.
This document defines the specifications for this ForCES protocol.
Haleplidis, et al. Expires September 5, 2009 [Page 6]
Internet-Draft ForCES Interoperability Draft March 2009
ForCES Protocol Transport Mapping Layer (ForCES TML) - A layer in
ForCES protocol architecture that uses the capabilities of
existing transport protocols to specifically address protocol
message transportation issues, such as how the protocol messages
are mapped to different transport media (like TCP, IP, ATM,
Ethernet, etc), and how to achieve and implement reliability,
multicast, ordering, etc. The ForCES TML specifications are
detailed in separate ForCES documents, one for each TML.
Haleplidis, et al. Expires September 5, 2009 [Page 7]
Internet-Draft ForCES Interoperability Draft March 2009
4. Testbed architecture
Most FEs and CEs should be located locally at the University of
Patras premises. But if some parties would like to participate but
cannot attend the interoperability test locally a connection over the
internet MAY be created.
The actual test will take place between FEs and CEs of different
implementors with different permutations.
4.1. Local configuration
Hardware/Software (CEs and FEs) that will be located within the
University of Patras premises, will be connected together using
switches and hubs. For each permutation there would be a different
subnet ranging starting from 192.168.1.xxx to 192.168.255.xxx to
distinguish them.
For each subnet there will be a machine with IP 192.168.xxx.2 which
will act as a network monitor using a network analyzer that should be
able to show the packets that are traversing the network.The IPs of
CEs and FEs will range from 192.168.xxx.3 to 192.168.xxx.254
This will help minimize packet interference with other machines and
make the testing and the validation easier
4.2. Distributed configuration
For parties that cannot participate locally there are two current
propositions:
1. A SCTP over IPsec (VPN) case, where CE and FE are part of a VPN.
2. SCTP over IP with a firewall that will allow only the CEs and FEs
IPs.
A number of public IPs will be provided by the University of Patras
will be provided for such a case.
Haleplidis, et al. Expires September 5, 2009 [Page 8]
Internet-Draft ForCES Interoperability Draft March 2009
5. Scenarios
All protocol messages of each scenario will be monitored using a
protocol network analyzer to test validity.
5.1. Scenario 1 - Pre-association Setup
While the Pre-association setup is not in the ForCES current scope it
is an essential step before CEs and FEs communicate. As the first
part in a succesfull CE-FE connection the participating CEs and FEs
should be able to be configured. In the Pre-association Phase the
following configuration items MUST be setup regarding the CEs:
o Which FE IDs should they be connected
o The IP of the corresponsing FEs
In the Pre-association Phase the following configuration items MUST
be setup regarding the FEs:
o Which CE IDs should they be connected
o The IP of the corresponsing CEs
Once each element is configured, Scenario 1 is successfull.
5.2. Scenario 2 - TML connection
For the current interoperability test, the SCTP will be used as TML.
The TML connection with the associating element is needed for the
scenario 2 to be successfull.
5.3. Scenario 3 - TML priority channel connection
The SCTP-TML draft [I-D.ietf-forces-sctptml] defines 3 priority
channels, with specific ports:
o High priority - Port number: 6700
o Medium priority - Port number: 6701
o Lower priority - Port number: 6702
Once these channels have been established with each associated
element, will the Scenario 3 be successfull.
Haleplidis, et al. Expires September 5, 2009 [Page 9]
Internet-Draft ForCES Interoperability Draft March 2009
5.4. Scenario 4 - Association Setup - Association Complete
Once the Pre-association phase has been complete in the previous 3
scenarios, CEs and FEs are ready to communicate using the ForCES
protocol, and enter the Association Setup stage. In this stage the
FEs attempts to join the NE. The following ForCES protocol messages
will be exchanged for each CE-FE pair:
o Association Setup Message (from FE to CE)
o Association Setup Response Message (from CE to FE)
Once the associations has been initialized scenario 4 will have been
successfull.
5.5. Scenario 5 - CE query
Once the Association Phase stage has been complete, the FEs and CEs
will enter the Established stage. In this stage the FE is
continuously updated or queried. The CE should query the FE a
specific value from the FE Object LFB and from the FE Protocol LFB.
An example from the FE Protocol LFB is the HeartBeat Timer (FEHI) and
from the FE Object LFB is the State of the LFB (FEState)
The following ForCES protocol messages will be exchanged:
o Query Message
o Query Response Message
5.6. Scenario 6 - Heartbeat monitoring
The Heartbeat (HB) Message is used for one ForCES element (FE or CE)
to asynchronously notify one or more other ForCES elements in the
same ForCES NE on its liveness. The default configuration of the
Heartbeat Policy of the FE is set to 0 which means, that the FE
should not generate any Heartbeat messages. the CE is responsible for
checking FE liveness by setting the PL header ACK flag of the message
it sends to AlwaysACK. In this Scenario the CE should send a
Heartbeat message with the ACK flag set to AlwaysACK and the FE
should respond.
The following ForCES protocol messages will be exchanged:
o Heartbeat Message
Haleplidis, et al. Expires September 5, 2009 [Page 10]
Internet-Draft ForCES Interoperability Draft March 2009
5.7. Scenario 7 - Simple Config Command
A config message is sent by the CE to the FE to configure LFB
components in the FE. A simple config command easily visilble and
metered would be to change the Heartbeat configuration. This will be
done in two steps:
1. Change the FE Heartbeat Policy (FEHBPolicy) to value 1, to force
the FE to send heartbeats.
2. After some heartbeats from the FE, the FE Heartbeat Interval
(FEHI) will be changed.
The following ForCES protocol messages will be exchanged:
o Config Message
o Config Response Message
5.8. Scenario 8 - Association Teardown
In the end, the association must be terminated. There are two
scenarios by which the association maybe terminated:
1. By stopping heartbeats from a FE or a CE.
2. By externally shutting down/rebooting a FE or a CE.
Both scenarios may be tested in the interoperability test.
The following ForCES protocol messages will be exchanged:
o Association Teardown Message
Haleplidis, et al. Expires September 5, 2009 [Page 11]
Internet-Draft ForCES Interoperability Draft March 2009
6. Acknowledgements
TBA
Haleplidis, et al. Expires September 5, 2009 [Page 12]
Internet-Draft ForCES Interoperability Draft March 2009
7. IANA Considerations
This memo includes no request to IANA.
Haleplidis, et al. Expires September 5, 2009 [Page 13]
Internet-Draft ForCES Interoperability Draft March 2009
8. Security Considerations
We should consider security issues if we have connections when there
are associations between CEs and FEs over the internet. Perhaps SCTP
over IPsec may be used.
TBA.
Haleplidis, et al. Expires September 5, 2009 [Page 14]
Internet-Draft ForCES Interoperability Draft March 2009
9. References
9.1. Normative References
[I-D.ietf-forces-model]
Halpern, J. and J. Salim, "ForCES Forwarding Element
Model", draft-ietf-forces-model-16 (work in progress),
October 2008.
[I-D.ietf-forces-protocol]
Dong, L., Doria, A., Gopal, R., HAAS, R., Salim, J.,
Khosravi, H., and W. Wang, "ForCES Protocol
Specification", draft-ietf-forces-protocol-21 (work in
progress), February 2009.
[I-D.ietf-forces-sctptml]
Salim, J. and K. Ogawa, "SCTP based TML (Transport Mapping
Layer) for ForCES protocol", draft-ietf-forces-sctptml-02
(work in progress), January 2009.
9.2. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552,
July 2003.
[RFC3654] Khosravi, H. and T. Anderson, "Requirements for Separation
of IP Control and Forwarding", RFC 3654, November 2003.
[RFC3746] Yang, L., Dantu, R., Anderson, T., and R. Gopal,
"Forwarding and Control Element Separation (ForCES)
Framework", RFC 3746, April 2004.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
Haleplidis, et al. Expires September 5, 2009 [Page 15]
Internet-Draft ForCES Interoperability Draft March 2009
Authors' Addresses
Evangelos Haleplidis
University of Patras
Patras,
Greece
Email: ehalep@ece.upatras.gr
Kentaro Ogawa
NTT Corporation
Tokyo,
Japan
Email: ogawa.kentaro@lab.ntt.co.jp
Xin-ping Wang
Huawei Technologies Co., Ltd.
China
Email: carly.wang@huawei.com
Haleplidis, et al. Expires September 5, 2009 [Page 16]
